EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

The sustainability of the electric steelmaking route is affected by several factors, such as the electric energy consumption, the waste production, the CO2 emission, as well as by the consumption of freshwater and the amount of wastewater. The improvement of the water management in the electric steelworks can lead to a reduction of their water footprint and impact on the surrounding environment and local community. To achieve this goal, the paper presents a work focused on the assessment of modifications of a water network of an Italian electric steelmaking plant in order to reduce the contaminant load of wastewater and allow its internal reuse. The work is part of the European project entitled “Environmental Impact Evaluation and Effective Management of Resources” (EIRES) funded by the Research Fund for Coal and Steel. Fluoride is the main contaminant that limits the possibility of the reuse of wastewater; it comes from the lubricant powder used in continuous casting and it contaminates water used for direct cooling of the product in the casting machine. For this reason, some solutions of treatment units addition to the current steel water network were evaluated. Sensitivity analyses were also carried out to evaluate the process behaviour to possible variation of features of the water to be treated. The evaluation was carried out by exploiting a simulation tool developed during the project through Aspen Plus® and especially its sub-model related to the water network. The main water parameters were monitored such as electrical conductivity, contaminant amount, pH and temperatures. The reuse of treated wastewater was then considered and some KPIs related to water consumption before and after the evaluated water network modifications were evaluated and compared.